Optical monitoring system for blood processing system

ABSTRACT

An optical monitoring system is provided for use with a blood processing system. The system includes a light source configured to illuminate a disposable flow circuit received in a centrifuge and a light detector configured to receive an image of the disposable flow circuit. A controller combines two or more of the images received by the light detector to generate a two-dimensional output. The output is used to control the separation of blood within the disposable flow circuit. The monitoring system may also be used to verify that the disposable flow circuit is suitable for use with the centrifuge or that the disposable flow circuit is properly aligned within the centrifuge. The monitoring system may be positioned outside of the centrifuge bucket which receives the centrifuge.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/058,514, filed Oct. 21, 2013, which is a continuation of U.S. patentapplication Ser. No. 14/112,969, filed Oct. 21, 2013, which is a U.S.national stage application of PCT Patent Application Serial No.PCT/US2012/056992, filed Sep. 25, 2012, which claims the benefit of andpriority of U.S. Patent Application Ser. No. 61/539,034, filed Sep. 26,2011, the contents of which are incorporated by reference herein.

DESCRIPTION Technical Field

The disclosure relates to blood treatment systems and methods. Moreparticularly, the disclosure relates to systems and methods foroptically detecting the characteristics of a disposable flow circuitmounted within a durable blood separation system and the fluid flowtherethrough.

BACKGROUND

Various blood processing systems now make it possible to collectparticular blood constituents, rather than whole blood, from a bloodsource. Typically, in such systems, whole blood is drawn from a bloodsource, the particular blood component or constituent is separated,removed, and collected, and the remaining blood constituents arereturned to the blood source. Removing only particular constituents isadvantageous when the blood source is a human donor or patient, becausepotentially less time is needed for the donor's body to return topre-donation levels, and donations can be made at more frequentintervals than when whole blood is collected. This increases the overallsupply of blood constituents, such as plasma and platelets, madeavailable for transfer and/or therapeutic treatment.

Whole blood is typically separated into its constituents throughcentrifugation. This requires that the whole blood be passed through acentrifuge after it is withdrawn from, and before it is returned to, theblood source. To avoid contamination and possible infection (if theblood source is a human donor or patient), the blood is preferablycontained within a sealed, sterile fluid flow system during the entirecentrifugation process. Typical blood processing systems thus include apermanent, reusable assembly containing the hardware (centrifuge, drivesystem, pumps, valve actuators, programmable controller, and the like)that spins and pumps the blood, and a disposable, sealed, and sterileflow circuit that is mounted in cooperation on the hardware.

The centrifuge engages and spins the disposable flow circuit during ablood separation step. As the flow circuit is spun by the centrifuge,the heavier (greater specific gravity) components of the whole blood inthe flow circuit, such as red blood cells, move radially outwardly awayfrom the center of rotation toward the outer or “high-G” wall of thecentrifuge. The lighter (lower specific gravity) components, such asplasma, migrate toward the inner or “low-G” wall of the centrifuge.Various ones of these components can be selectively removed from thewhole blood by providing appropriately located channeling seals andoutlet ports in the flow circuit. For example, in one blood separationprocedure, plasma is separated from cellular blood components andcollected, with the cellular blood components and a replacement fluidbeing returned to the blood source.

One disadvantage of known systems is that they may not include adequatesafeguards to ensure that the proper disposable flow circuit is used andthat the disposable flow circuit is properly aligned within thecentrifuge. If an inappropriate flow circuit is used with the centrifuge(or if the flow circuit is improperly installed), damage can be done tothe flow circuit and/or the centrifuge. Even if the flow circuit andcentrifuge are not damaged, the blood may be improperly fractionated andprocessed, which reduces the effectiveness of the system and can even beharmful to a human connected to the system.

It is known to employ an optical sensor system to monitor the flow ofblood and/or blood components through the flow circuit in the centrifugeand determine various characteristics of the flow. These optical sensorsystems can be characterized as either one- or two-dimensional types. Incomparison to known systems, it may be advantageous to provide anoptical monitoring system with improved flow control functionality,additional functionality (beyond flow control), and/or alternativeplacement within a blood separation device.

SUMMARY

There are several aspects of the present subject matter which may beembodied separately or together in the devices and systems described andclaimed below. These aspects may be employed alone or in combinationwith other aspects of the subject matter described herein, and thedescription of these aspects together is not intended to preclude theuse of these aspects separately or the claiming of such aspectsseparately or in different combinations as set forth in the claimsappended hereto.

In one aspect, blood processing system is provided with a disposableflow circuit, a centrifuge, and a monitoring system. The disposable flowcircuit is configured for the flow of whole blood and/or a separatedblood component therethrough. The centrifuge is configured to receive atleast a portion of the disposable flow circuit and separate at least oneblood component from blood flowing through the disposable flow circuit.The monitoring system is configured to directly monitor the disposableflow circuit received by the centrifuge and includes a light source, alight detector, and a controller. The light source is configured toilluminate the portion of the disposable flow circuit received by thecentrifuge. The light detector is configured to receive an image of theportion of the disposable flow circuit received by the centrifuge. Thecontroller is configured to combine two or more of the images receivedby the light detector, generate a two-dimensional output, and controlthe separation of blood in the disposable flow circuit based at least inpart on the output.

In another aspect, a method is provided for controlling a bloodseparation procedure. The method includes separating at least one bloodcomponent from blood in a centrifuge. Light is applied to the interiorof the centrifuge and an image of the interior of the centrifuge isreceived. Two or more of the received images are combined and then atwo-dimensional output is generated based, at least in part, on theimages. The blood separation procedure is controlled based, at least inpart, on the output.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary blood separation device, inaccordance with an aspect of the present disclosure;

FIG. 2 is a diagrammatic view of an exemplary disposable flow circuitthat may be used in combination with the separation device of FIG. 1;

FIG. 3 is a side elevational view, with portions broken away and insection, of the separation device of FIG. 1, with a centrifuge bowl andspool of the system being shown in their operating position;

FIG. 4 is a side elevational view, with portions broken away and insection, of the separation device of FIG. 1, with the centrifuge bowland spool shown in an upright position for receiving a blood separationchamber;

FIG. 5 is a top perspective view of the centrifuge spool of FIG. 4 inits upright position and carrying the blood separation chamber of theflow circuit of FIG. 2;

FIG. 6 is a plan view of the blood separation chamber of FIG. 5, out ofassociation with the spool;

FIG. 7 is an exploded perspective view of a fluid processing cassette ofthe flow circuit of FIG. 2;

FIG. 8 is a perspective view of an underside of the fluid processingcassette of FIG. 7;

FIG. 9 is a perspective view of a cassette holder of the bloodprocessing system of FIG. 1;

FIG. 10 is an enlarged perspective view of an interface ramp carried bythe centrifuge in association with the blood separation chamber, showingthe centrifugally separated red blood cell layer, plasma layer, andinterface within the chamber when in a desired location on the ramp;

FIG. 11 is an enlarged perspective view of the interface ramp shown inFIG. 10, showing the red blood cell layer and interface at an undesiredhigh location on the ramp;

FIG. 12 is an enlarged perspective view of the interface ramp shown inFIG. 10, showing the red blood cell layer and interface at an undesiredlow location on the ramp;

FIG. 13 is a side perspective view of the centrifuge, with a portion ofthe centrifuge bucket broken away to show the bowl and spool of thecentrifuge in the operating position;

FIG. 14 is a side section view of the centrifuge bowl and spool of FIG.13;

FIG. 15 is a diagrammatic view of a blood separation chamberincorporating an identification feature;

FIG. 16 is a detail view of the identification feature of FIG. 15; and

FIG. 17 is a diagrammatic view of a blood separation chamberincorporating an alignment feature and received within a centrifuge.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The embodiments disclosed herein are for the purpose of providing adescription of the present subject matter, and it is understood that thesubject matter may be embodied in various other forms and combinationsnot shown in detail. Therefore, specific embodiments and featuresdisclosed herein are not to be interpreted as limiting the subjectmatter as defined in the accompanying claims.

Blood processing systems according to the present disclosure include aseparation device, which may be variously provided without departingfrom the scope of the present disclosure. FIG. 1 shows an exemplarydurable separation device 10 that may be employed in blood processingsystems according to the present disclosure. The separation device 10may be provided according to known design, such as the system currentlymarketed as the AMICUS® separator by Fenwal, Inc. of Lake Zurich, Ill.,which is an affiliate of Fresenius Kabi AG of Bad Homburg, Germany, asdescribed in greater detail in U.S. Pat. No. 5,868,696, which is herebyincorporated herein by reference. The separation device 10 can be usedfor processing various fluids, but is particularly well suited forprocessing whole blood and other suspensions of biological cellularmaterials. While fluid treatment principles will be described hereinwith reference to one particular system, it should be understood thatthese principles may be employed with other blood processing systems andseparation devices without departing from the scope of the presentdisclosure.

FIG. 2 illustrates a disposable flow circuit 12 that may be used incombination with the separation device 10 of FIG. 1 to provide a bloodprocessing system. The flow circuit 12 includes a variety of tubing anda number of components, only some of which will be described herein ingreater detail. It should be understood that FIG. 2 illustrates only oneexample of a flow circuit which may be used in combination with theseparation device 10 of FIG. 1 and differently configured flow circuitsmay also be employed without departing from the scope of the presentdisclosure.

The illustrated flow circuit 12 is a “two needle” system, which includesa pair of blood source access devices 14 and 14 a (e.g., phlebotomyneedles) for fluidly connecting a blood source with the flow circuit 12.The blood source access devices 14 and 14 a are connected by tubing to aleft cassette 16, which will be described in greater detail herein. Oneof the blood source access devices 14 is used to draw blood from theblood source into the flow circuit 12 and is connected to the leftcassette 16 by a y-connector 18. The other leg of the y-connector 18 isconnected to tubing 20 which leads to a middle cassette 16 a. The tubing20 is connected, through the middle cassette 16 a, to additional tubing22, which includes a container access device 24 (e.g., a sharpenedcannula or spike connector) for accessing the interior of ananticoagulant container (not illustrated). During a blood treatmentoperation, anticoagulant from the anticoagulant container may be addedto the blood from the blood source at the y-connector 18 prior toentering the left cassette 16.

The other blood source access device 14 a is used to deliver or returnblood, a blood component, and/or some other replacement fluid to theblood source and is also connected to the left cassette 16 by ay-connector 26. The other leg of the y-connector 26 is connected totubing 28 connected at its other end to a container access device 30.Although not illustrated, the container access device 30 may beassociated with a container having an amount of fluid (e.g., saline) tobe used to prime the flow circuit 12 and/or delivered to the bloodsource via the blood source access device 14 a.

The left cassette 16 also includes tubing 32 which is connected to ablood separation chamber 34 of the flow circuit 12 for flowinganticoagulated blood thereto. The blood separation chamber 34 separatesthe blood into its constituent parts (as will be described in greaterdetail herein) and returns the blood components to the flow circuit 12.In one embodiment, cellular blood components are returned to the middlecassette 16 a of the flow circuit 12 from the blood separation chamber34 via tubing 36, while substantially cell-free plasma is returned to aright cassette 16 b of the flow circuit 12 from the blood separationchamber 34 via tubing 38. The cellular blood components may be pumped tothe left cassette 16 via tubing 40, where they are returned to the bloodsource. The plasma may be pumped back to the left cassette 16 via tubing42 for return to the blood source and/or it may be pumped into acontainer 44 via different tubing 46. The destination of the plasma (andthe other fluids passing through the cassettes) depends upon theactuation of the various valves of the cassettes, as will be describedin greater detail herein. The various tubing connected to the bloodseparation chamber 34 are bundled in an umbilicus 48, which will bedescribed in greater detail herein.

Additional tubing may be connected from one port of a cassette toanother port of the same cassette, so as to form tubing loops 50 whichinteract with a fluid flow element or pump to flow fluid through theflow circuit 12, as will be described in greater detail herein.

A. The Centrifuge

The separation device 10 includes a centrifuge 52 (FIGS. 3 and 4) usedto centrifugally separate blood components. The separation device 10 maybe programmed to separate blood into a variety of components (e.g.,platelet-rich plasma and red cells). For illustrative purposes, atherapeutic plasma exchange procedure, in which the centrifuge 52separates whole blood into cellular components and cell fragments (e.g.,red blood cells and platelets) and substantially cell-free plasma, willbe described herein. However, the principles described and claimedherein may be employed with other blood separation procedures withoutdeparting from the scope of the present disclosure.

The illustrated centrifuge 52 is of the type shown in U.S. Pat. No.5,316,667 to Brown et al., which is incorporated herein by reference.The centrifuge 52 comprises a bowl 54 and a spool 56 which are receivedwithin a bucket 57. The bowl 54 and spool 56 are pivoted on a yoke 58between an operating position (FIG. 3) and a loading/unloading position(FIG. 4). The centrifuge 52 is housed within the bucket 57 in theinterior of the separation device 10, so a door 60 is provided to allowaccess to the centrifuge 52 for loading and unloading the bloodseparation chamber 34, as will be described in greater detail herein.The door 60 remains closed during operation to protect and enclose thecentrifuge 52.

When in the loading/unloading position, the spool 56 can be opened bymovement at least partially out of the bowl 54, as FIG. 4 shows. In thisposition, the operator wraps the flexible blood separation chamber 34about the spool 56 (see FIG. 5). Closure of the spool 56 and bowl 54encloses the chamber 34 for processing. When closed, the spool 56 andbowl 54 are pivoted into the operating position of FIG. 3 for rotationabout an axis.

B. The Blood Separation Chamber

FIG. 6 shows a representative embodiment of a blood separation chamber34 which may be used in connection with the present disclosure. Thechamber 34 shown in FIG. 6 allows for either single- or multi-stageprocessing. When used for multi-stage processing, a first stage 62separates whole blood into first and second components. Depending on thenature of the separation procedure, one of the components may betransferred into a second stage 64 for further processing.

As FIGS. 5 and 6 best show, there are three ports 66, 68, and 70associated with the first stage 62. Depending on the particular bloodprocessing procedure, the ports may have different functionality. Forexample, in a therapeutic plasma exchange procedure, the port identifiedat 70 is used for conveying blood from a blood source into the firststage 62 (via tubing 32 of the flow circuit 12). During such atherapeutic plasma exchange procedure, the other two ports 66 and 68serve as outlet ports for passing separated blood components from thefirst stage 62 to the flow circuit 12 (via tubing 36 and 38,respectively). More particularly, the first outlet port 68 conveys a lowdensity blood component from the first stage 62, while the second outletport 66 conveys a high density blood component from the first stage 62.

In a method of carrying out single-stage processing, one of theseparated components is returned to the blood source, while the other isremoved from the first stage 62 for further processing via an adsorptiondevice (not illustrated). For example, when carrying out a therapeuticplasma exchange procedure, whole blood in the first stage 62 isseparated into cellular components (i.e., a high density component) andsubstantially cell-free plasma (i.e., a low density component). Theplasma is removed from the first stage 62 via the first outlet port 68for further processing by the adsorption device, while the cellularcomponents are removed from the first stage 62 via the second outletport 66 and returned to the blood source. After the plasma has beentreated by the adsorption device, it may be returned to the bloodsource.

If multi-stage processing is required, one of the components will betransferred from the first stage 62 to the second stage 64 via a port 72associated with the second stage 64. The component transferred to thesecond stage 64 is further fractionated into sub-components, with one ofthe sub-components being removed from the second stage 64 via an outletport 74 and the other sub-component remaining in the second stage 64. Inthe illustrated embodiment, the ports 66, 68, 70, 72, and 74 arearranged side-by-side along the top transverse edge of the chamber 34.

While the same ports 66, 68, and 70 of the first stage 62 are used as inthe above-described therapeutic plasma exchange procedure, the ports 66and 70 have different functionality in a multi-stage separationprocedure. In one method of multi-stage operation, such as plateletcollection, blood enters the first stage 62 via the port 66 and isseparated into red blood cells (i.e., the high density blood component)and platelet-rich plasma (i.e., the low density blood component). Thered blood cells are returned to the blood source (via the port 70),while the platelet-rich plasma is conveyed out of the first stage 62(via the first outlet port 68) and into the second stage 64 (via theinlet port 72). In the second stage 64, the platelet-rich plasma isseparated into platelet-poor plasma and platelet concentrate. Theplatelet-poor plasma is removed from the second stage 64 (via the outletport 74), leaving platelet concentrate in the second stage 64 forresuspension and transfer to one or more storage containers.

As best shown in FIG. 5, the tubing umbilicus 48 of the flow circuit 12is attached to the ports 66, 68, 70, 72, and 74. The umbilicus 48interconnects the first and second stages 62 and 64 with each other andwith the components of the flow circuit 12 positioned outside of thecentrifuge 52. As FIG. 3 shows, a non-rotating (zero omega) holder 76holds the upper portion of the umbilicus 48 in a non-rotating positionabove the spool 56 and bowl 54. A holder 78 on the yoke 58 rotates themid-portion of the umbilicus 48 at a first (one omega) speed about thesuspended spool 56 and bowl 54. Another holder 80 (FIGS. 4 and 5)rotates the lower end of the umbilicus 48 at a second speed twice theone omega speed (the two omega speed), at which speed the spool 56 andbowl 54 also rotate. This known relative rotation of the umbilicus 48keeps it untwisted, in this way avoiding the need for rotating seals.

As FIG. 6 shows, a first interior seal 82 is located between the lowdensity outlet port 68 and the high density outlet port 66. A secondinterior seal 84 is located between the high density outlet port 66 andthe blood inlet port 70. The interior seals 82 and 84 form a fluidpassage 86 (an outlet for high density blood components in a therapeuticplasma exchange procedure) and a low density collection region 88 in thefirst stage 62. The second seal 84 also forms a fluid passage 90 (ablood inlet in a therapeutic plasma exchange procedure) in the firststage 62.

C. The Cassettes

Blood entering the blood separation chamber 34 is pumped thereinto byone or more pumps 92 of the separation device 10 (FIGS. 1 and 2) actingupon one or more of the tubing loops 50 extending from the cassettes16-16 b of the flow circuit 12 (FIG. 2). An exemplary cassette 16 isillustrated in greater detail in FIGS. 7 and 8, while the pumps 92 andassociated cassette holder 94 are shown in greater detail in FIG. 9.

Before beginning a given blood processing and collection procedure, theoperator loads various components of the flow circuit 12 onto the slopedfront panel 96 and centrifuge 52 of the separation device 10. Asdescribed above, the blood separation chamber 34 and the umbilicus 48 ofthe flow circuit 12 are loaded into the centrifuge 52, with a portion ofthe umbilicus 48 extending outside of the interior of the separationdevice 10, as shown in FIG. 3. The sloped front panel 96 of theseparation device 10 includes at least one cassette holder 94 (three inthe illustrated embodiment), each of which is configured to receive andgrip an associated cassette 16-16 b of the flow circuit 12.

Each cassette 16-16 b, one of which is shown in FIGS. 7 and 8, includesan injection molded body 98 that is compartmentalized by an interiorwall 100 (FIG. 8) to present or form a topside 102 (FIG. 7) and anunderside 104 (FIG. 8). For the purposes of description, the topside 102is the side of the cassette 16 that, in use, faces away from theseparation device 10, while the underside 104 faces towards theseparation device 10. A flexible diaphragm 106 overlies and peripherallyseals the underside 104 of the cassette 16. A generally rigid upperpanel 108 overlies the topside 102 of the cassette 16 and is sealedperipherally and to the raised channel-defining walls in the cassette16, as described later.

In one embodiment, the cassette 16, the interior wall 100, and the upperpanel 108 are made of a rigid medical grade plastic material, while thediaphragm 106 is made of a flexible sheet of medical grade plastic. Theupper panel 108 and the diaphragm 106 are sealed about their peripheriesto the peripheral edges of the top- and undersides 102, 104 of thecassette 16, respectively.

As shown in FIGS. 7 and 8, the top- and undersides 102, 104 of thecassette 16 contain preformed cavities. On the underside 104 of thecassette 16 (FIG. 8), the cavities form an array of valve stations 110and an array of pressure sensing stations 112. On the topside 102 of thecassette 16 (FIG. 7), the cavities form an array of channels or paths114 for conveying liquids. The valve stations 110 communicate with theliquid paths 114 through the interior wall 100 to interconnect them in apredetermined manner. The sensing stations 112 also communicate with theliquid paths 114 through the interior wall 100 to sense pressures inselected regions. The number and arrangement of the liquid paths 114,the valve stations 110, and the sensing stations 112 can vary but, inthe illustrated embodiment, the cassette 16 provides nineteen liquidpaths 114, ten valve stations 110, and four sensing stations 112.

The valve and sensing stations 110, 112 resemble shallow wells open onthe cassette underside 104 (FIG. 8). Upstanding edges 116 rise from theinterior wall 100 and peripherally surround the valve and sensingstations 110, 112. The valve stations 110 are closed by the interiorwall 100 on the topside 102 of the cassette 16, except that each valvestation 110 includes a pair of through holes or ports 118 in theinterior wall 100. The ports 118 each open into selected differentliquid paths 114 on the topside 102 of the cassette 16.

The sensing stations 112 are likewise closed by the interior wall 100 onthe topside 102 of the cassette 16, except that each sensing station 112includes three through holes or ports 120 in the interior wall 100 (FIG.8). The ports 120 open into selected liquid paths 114 on the topside 102of the cassette 16. These ports 120 channel liquid flow among theselected liquid paths 114 through the associated sensing station 112.

In one embodiment, the flexible diaphragm 106 overlying the underside104 of the cassette 16 is sealed by ultrasonic welding to the upstandingperipheral edges 116 of the valve and sensing stations 110, 112. Thisisolates the valve stations 110 and sensing stations 112 from each otherand the rest of the system. In an alternative embodiment, the flexiblediaphragm 106 can be seated against the upstanding edges 116 by anexternal positive force applied by the cassette holder 94 against thediaphragm 106. The positive force, like the ultrasonic weld,peripherally seals the valve and sensing stations 110, 112.

The localized application of additional positive force (referred toherein as a “closing force”) upon the intermediate region of thediaphragm 106 overlying a valve station 110 serves to flex the diaphragm106 into the valve station 110. Such closing force is provided by thecassette holder 94, as will be described in greater detail herein. Thediaphragm 106 seats against one of the ports 118 to seal the port 118,which closes the valve station 110 to liquid flow. Upon removal of theclosing force, fluid pressure within the valve station 110, theapplication of a vacuum to the outer surface of the diaphragm 106,and/or the plastic memory of the diaphragm 106 itself unseats thediaphragm 106 from the port 118, opening the valve station 110 to liquidflow.

Upstanding channel sides or edges 122 rise from the interior wall 100 toperipherally surround and define the liquid paths 114, which are open onthe topside 102 of the cassette 16. The liquid paths 114 are closed bythe interior wall 100 on the underside 104 of the cassette 16, exceptfor the ports 118, 120 of the valve and sensing stations 110, 112 (FIG.8). The rigid panel 108 overlying the topside 102 of the cassette 16 issealed by ultrasonic welding to the upstanding peripheral edges 122,sealing the liquid paths 114 from each other and the rest of the system.

In the illustrated embodiment, ten pre-molded tube connectors 124 extendout along opposite side edges 126, 128 of each cassette 16. The tubeconnectors 124 are arranged five on one side edge 126 and five on theother side edge 128. The other side edges 130 of the cassette 16, asillustrated, are free of tube connectors. The tube connectors 124 areassociated with external tubing (FIG. 2) to associate the cassettes 16with the remainder of the flow circuit 12, as described above.

The tube connectors 124 communicate with various interior liquid paths114, which constitute the liquid paths of the cassette 16 through whicha fluid enters or exits the cassette 16. The remaining interior liquidpaths 114 of the cassette 16 constitute branch paths that link theliquid paths 114 associated with the tube connectors 124 to each otherthrough the valve stations 110 and sensing stations 112.

D. The Cassette Holders And Pumps

Turning now to the cassette holders 94 (FIG. 9), each receives and gripsone of the cassettes 16-16 b along the two opposed sides edges 130 inthe desired operating position. The cassette holder 94 includes a pairof peristaltic pump stations 92. When the cassette 16 is gripped by thecassette holder 94, tubing loops 50 extending from the cassette 16 (FIG.2) make operative engagement with the pump stations 92. The pumpstations 92 are operated to cause fluid flow through the cassette 16.

The flexible diaphragm 106 covering the underside 104 of the cassette 16is urged into intimate contact with a valve and sensor array or assembly132 by the cassette holder 94. The valve assembly 132 acts in concertwith the valve stations 110 and sensing stations 112 of the cassette 16.The valve assembly 132 illustrated in FIG. 9 includes ten valveactuators 134 and four pressure sensing transducers 136. The valveactuators 134 and the pressure sensing transducers 136 are mutuallyarranged in the same layout as the valve stations 110 and sensingstations 112 on the underside 104 of the cassette 16. When the cassette16 is gripped by the cassette holder 94, the valve actuators 134 alignwith the cassette valve stations 110. At the same time, the pressuresensing transducers 136 mutually align with the cassette sensingstations 112.

In one embodiment, each valve actuator 134 includes an electricallyactuated solenoid pin or piston 138. Each piston 138 is independentlymovable between an extended position and a retracted position. When inits extended position, the piston 138 presses against the region of thediaphragm 106 that overlies the associated valve station 110. In thisposition, the piston 138 flexes the diaphragm 106 into the associatedvalve station 110, thereby sealing the associated valve port 118. Thiscloses the valve station 110 to liquid flow. When in its retractedposition, the piston 138 does not apply force against the diaphragm 106.As before described, the plastic memory of the diaphragm 106 may be suchthat the removal of force is sufficient for the diaphragm to unseatsfrom the valve port 118, thereby opening the valve station 110 to liquidflow. Alternatively, a vacuum may be applied to the diaphragm 106, forexample by the vacuum port 140 illustrated in FIG. 9, to actively unseatthe diaphragm 106 from the valve port 118.

The pressure sensing transducers 136 sense liquid pressures in thesensing stations 112 of the cassette 16. The sensed pressures aretransmitted to a controller of the separation device 10 as part of itsoverall system monitoring function. If provided, the vacuum port 140 ofthe cassette holder 94 may provide suction to the diaphragm 106 of thecassette 16, drawing it into close contact with the transducers 136 formore accurate pressure readings.

E. Blood Separation

As described above, the centrifuge 52 rotates the blood separationchamber 34, thereby centrifugally separating whole blood received from ablood source into component parts, e.g., red blood cells, plasma, andbuffy coat comprising platelets and leukocytes.

By way of example, in a therapeutic plasma exchange procedure, the fluidpassage 90 channels blood directly into the circumferential flow pathimmediately next to the low density collection region 88. As shown inFIG. 10, the blood separates into an optically dense layer 142containing cellular components, which forms as cellular components moveunder the influence of centrifugal force toward the high-G (outer) wall144. The optically dense layer 142 will include red blood cells (and,hence, will be referred to herein as the “RBC layer”) but, depending onthe speed at which the centrifuge 52 is spun, other cellular components(e.g., larger white blood cells and platelets) may also be present inthe RBC layer 142.

The movement of the component(s) of the RBC layer 142 displaces lessdense blood components radially toward the low-G (inner) wall 146,forming a second, less optically dense layer 148. The less opticallydense layer 148 includes plasma (and, hence, will be referred to hereinas the “plasma layer”) but, depending on the speed at which thecentrifuge 52 is rotated and the length of time that the blood isresident in the centrifuge, other components (e.g., platelets andsmaller white blood cells) may also be present in the plasma layer 148.

The transition between the formed cellular blood components and theliquid plasma component is generally referred to as the interface 150(FIG. 10). Platelets and white blood cells (which have a density greaterthan plasma and usually less than red blood cells) typically occupy thistransition region, although that also varies with centrifuge speed andresidence time, as is well known in the technical field.

The location of the interface 150 within the chamber 34 can dynamicallyshift during blood processing, as FIGS. 11 and 12 show. If the locationof the interface 150 is too high (that is, if it is too close to thelow-G wall 146 and the removal port 68, as FIG. 11 shows), cellularcomponents can spill over and into the low density collection region 88,adversely affecting the quality of the low density components (typicallyplasma). On the other hand, if the location of the interface 150 is toolow (that is, if it resides too far away from the low-G wall 146, asFIG. 12 shows), the collection efficiency of the separation device 10may be impaired.

As FIG. 10 shows, a ramp 152 extends from the high-G wall 144 of thebowl 54 at an angle across the low density collection region 88. Theangle, measured with respect to the axis of the first outlet port 68 isabout 30° in one embodiment. FIG. 10 shows the orientation of the ramp88 when viewed from the low-G wall 146 of the spool 56. FIG. 6 shows, inphantom lines, the orientation of the ramp 152 when viewed from thehigh-G wall 144 of the bowl 54.

Further details of the angled relationship of the ramp 152 and the firstoutlet port 68 can be found in U.S. Pat. No. 5,632,893 to Brown et al.,which is incorporated herein by reference.

The ramp 152 forms a tapered wedge that restricts the flow of fluidtoward the first outlet port 68. The top edge of the ramp 152 extends toform a constricted passage 154 along the low-G wall 146. The plasmalayer 148 must flow through the constricted passage 154 to reach thefirst outlet port 68.

As FIG. 10 shows, the ramp 152 makes the interface 150 between the RBClayer 142 and the plasma layer 148 more discernible for detection,displaying the RBC layer 142, plasma layer 148, and interface 150 forviewing through the high-G wall 144 of the chamber 34.

Further details of the separation chamber 34 and its operation may befound in U.S. Pat. No. 5,316,667, which is incorporated by reference.

F. The Optical Monitoring System

The separation device 10 includes an optical monitoring system 156 (FIG.13) which is configured to directly monitor the disposable flow circuit12 in the centrifuge 52. The illustrated monitoring system 156 includesa light source 158 and a light detector or image sensor 160. In theembodiment of FIG. 13, the monitoring system 156 is shown with one lightsource 158 and one light detector 160, but monitoring systems with aplurality of light source and/or a plurality of light detectors may alsobe employed without departing from the scope of the present disclosure.As will be described in greater detail herein, the monitoring system 156may be configured to detect characteristics of flow through the flowcircuit 12 (e.g., the location of the interface 150 on the ramp 152)and/or characteristics of the flow circuit 12 itself (such as, but notlimited to, placement, positioning, and suitability of the circuit). Themonitoring system 156 generates an output based on the images itobserves and the output is used to control the flow of fluid through theflow circuit 12 (e.g., controlling flow to adjust the position of theinterface 150 on the ramp 152) and/or whether a blood processingprocedure will be initiated or continued.

In one embodiment, the monitoring system 156 is positioned outside ofthe centrifuge 52. To allow the monitoring system 156 to directlymonitor the blood separation chamber 34, the centrifuge bowl 54 may betransparent to the light emitted by the light source 158 in the region162 where the bowl 54 overlies the interface ramp 152 (FIGS. 13 and 14).In the illustrated embodiment, the region 162 comprises a window cut outin the bowl 54. The remainder of the bowl 54 that lies in the path ofthe monitoring system 156 may be comprised of an opaque or lightabsorbing material.

In the illustrated embodiment, the monitoring system 156 is positionedoutside of the centrifuge bucket 57 (FIG. 13). The yoke 58 rotates at aone omega speed as the spool 56 and bowl 54 rotate at a two omega speed.In embodiments where the monitoring system 156 is positioned outside ofthe centrifuge bucket 57, the light source 158 is stationary and doesnot rotate. Accordingly, the window 162 and ramp 152 will not always bein the field of view of the monitoring system 156. In one embodiment,the monitoring system 156 may be provided in an “always on” state,wherein all of the components and functionality employed during amonitoring state (i.e., the time when the blood separation chamber 34 isvisible to the monitoring system 156 through the window 162) areemployed and functional at all times during a blood separationprocedure. For example, the light source 158 may be configured tocontinuously transmit light to the centrifuge 52, even when the window162 (and, hence, the blood separation chamber 34) are not in the fieldof view of the monitoring system 156.

In other embodiments, the monitoring system 156 is provided with anelectronic timing system for triggering full operation of the monitoringsystem 156 only when the blood separation chamber 34 (or an area ofinterest thereof) is visible to the monitoring system 156. Theelectronic timing system may include any of a variety of triggeringmechanisms, including (but not limited to) an optical triggeringmechanism, a mechanical triggering mechanism, and/or a magnetictriggering system. In one example of an optical triggering system, thewindow 162 and/or an area of interest of the blood separation chamber 34is physically bounded at its leading and/or trailing edges by markershaving a known intensity. When the monitoring system 156 detects amarker at the leading edge, it is an indication for the monitoringsystem 156 to become fully functional and initiate a monitoring statethat is operative until a marker at the trailing edge has been detected,at which time the monitoring state may be deactivated. These markers mayalso serve as calibration features which act as a baseline against whichany other detected light intensities are compared to account forvariations in illumination and sensor sensitivity. In anotherembodiment, a direct drive system is employed and the position of thewindow 162 with respect to the monitoring system 156 is known in termsof the rotational location of the motor. In this case, the electronictiming system may function to turn the monitoring system 156 on and offdepending on the rotational location of the motor.

Turning now to the light source 158 of the monitoring system 156, it ispositioned and oriented to illuminate a portion of the flow circuit 12received within the centrifuge 52 (i.e., the blood separation chamber34). The light source 158 may be configured to continuously illuminatethe blood separation chamber 34 during a monitoring state or may beintermittently operated (e.g., to provide stroboscopic illumination)during a monitoring state.

The light source 158 may be variously configured without departing fromthe scope of the present disclosure. For example, the light source 158may include at least one light emitting diode, but may alternatively (oradditionally) include any other suitable source of light. In general, asource of light would be considered suitable if it is capable oftransmitting enough light to the blood separation chamber 34 that thelight detector 160 will be able to detect an image thereof.

The monitoring system 156 is not limited to one light source 158, butmay include a plurality of light sources. If the monitoring system 156includes a plurality of light sources, the lights produced may havedifferent wavelengths. The light sources may be operated simultaneouslyor independently of each other (e.g., sequentially).

The light detector 160 (FIG. 13) is configured to receive an image ofthe blood separation chamber 34, which may include both the bloodseparation chamber 34 itself, as well as the flow of fluid therethrough.As used in this context, the term “image” is to be broadly construed torefer to the light received by the light detector 160, and may includeone- or two-dimensional distributions of light. The light detector 160may be variously configured without departing from the scope of thepresent disclosure. For example, the light detector 160 may be providedas a linear array-type sensor (e.g., a charge-coupled device orphotodiode array) which is configured to receive a one-dimensional imageof the blood separation chamber 34. In another embodiment, the lightdetector 160 is instead provided as a two-dimensional array sensor andis configured to receive a two-dimensional image of the blood separationchamber 34. The light detector 160 may be otherwise configured withoutdeparting from the scope of the present disclosure. As described above,the area of interest of the centrifuge 52 (i.e., the transparent window162 in the illustrated embodiment) may not be stationary with respect tothe monitoring system 156, in which case it may be advantageous for thescan rate of the light detector 160 to be coupled to the rotationalspeed of the centrifuge 52 such that the same area of the bloodseparation chamber 34 is always scanned by the light detector 160. Themonitoring system 156 is not limited to one light detector 160, but mayinclude a plurality of light detectors.

In an exemplary procedure, the monitoring system 156 may be configuredto determine the location of the interface 150 on the ramp 152 and (ifnecessary) adjust the flow of fluid through the blood separation chamber34 to move the interface 150 to a target location on the ramp 152. Insuch an embodiment, the interface ramp 152 may be made of a lighttransmissive material such that, when the window 162 is in the field ofview of the monitoring system 156, light from the light source 158 willpass through the window 162 of the bowl 54 and the ramp 152. The spool56 may carry a light reflective material 164 (FIG. 14) behind theinterface ramp 152 to enhance its reflective properties. The lightreflective material 164 of the spool 56 reflects incoming light receivedfrom the light source 158 out through the window 162 of the bowl 54,where it is detected by the light detector 160 to form an image. Thelight detector 160 may detect a plurality of images during a singlemonitoring state or revolution of the centrifuge 52. The monitoringsystem 156 may include a focusing lens and/or reflectors with whichlight returning from the centrifuge 52 interacts prior to receipt by thelight detector 160.

The monitoring system 156 also includes a controller, which may be thecentral controller of the separation device 10 or may be a separatecomponent that interacts with the central controller. The controller isconfigured to combine two or more of the images sequentially received orscanned by the light detector 160 and generate a two-dimensional output.The controller may employ any of a variety of digital image processingtechniques, such as filtering, diffusion, and edge detection in order toextract information from the two-dimensional output/image. Compared toknown one-dimensional systems, monitoring systems according to thepresent disclosure have improved resolution (including multi-megapixelimages of the small ramp 152 and window 162 with proper optics) andsignal-to-noise ratio. Further, the effect of any noise or distortionpresent at the area of interest analyzed by the system is reduced byconsidering multiple images, examining the entire length of (or at leasta greater portion of) the interface 150, and generating atwo-dimensional image/output. Also, it is possible to determine moreinformation regarding the interface 150 (e.g., the thickness of theinterface 150, whether the interface 150 is angled, particulate flux,etc.). Compared to known two-dimensional sensor systems, monitoringsystems according to the present disclosure may employ an “always on”light source 158 and do not require precise strobing of a light sourceto capture the areas of interest. Additionally, monitoring systemsaccording to the present disclosure may be less susceptible toimage-smearing, which may be more prevalent in known two-dimensionalsensor systems due to the combination of slow frame rate and fastcentrifugal motion of the area of interest.

The controller uses the two-dimensional output to control the flow offluid through the flow circuit 12. In particular, the controllertransmits the two-dimensional output (which represents the location ofthe interface 150 on the ramp 152) to an interface command element ormodule. The command element may include a comparator, which compares thetwo-dimensional interface location output with a desired interfacelocation to generate an error signal. The error signal may take a numberof forms but, in one embodiment, is expressed in terms of a targeted redblood cell percentage value (i.e., the percentage of the ramp 152 whichshould be occupied by the RBC layer 142).

When the control value is expressed in terms of a targeted red bloodcell percentage value, a positive error signal indicates that the RBClayer 142 on the ramp 152 is too large (as FIG. 11 shows). The interfacecommand element generates a signal to adjust an operational parameteraccordingly, such as by reducing the rate at which plasma is removedthrough the first outlet port 68 under action of one or more of thepumps 92. The interface 150 moves away from the constricted passage 154toward the desired control position (as FIG. 10 shows), where the errorsignal is zero.

A negative error signal indicates that the RBC layer 142 on the ramp 152is too small (as FIG. 12 shows). The interface command element generatesa signal to adjust an operational parameter accordingly, such as byincreasing the rate at which plasma is removed through the first outletport 68. The interface 150 moves toward the constricted passage 154 tothe desired control position (FIG. 10), where the error signal is againzero.

Alternatively, or in addition to determining the location of theinterface 150, the controller may be configured to determine othercharacteristics of fluid flow through the blood separation chamber 34based (at least in part) on the two-dimensional image/output. The flowcharacteristics determinable by the optical monitoring system 156 maydepend, in part, on the nature of the light source 158 (e.g., thewavelength of the light produced by the light source 158) and theinclusion of additional associated components (e.g., filters). The bloodseparation chamber 34 and/or the centrifuge 52 may also be speciallyconfigured to enhance the functionality of the optical monitoring system156 (e.g., by providing features which allow a single light detector 160to have different views of the area of interest). For example, thecontroller may be configured to use the two-dimensional image/output itcreates to determine turbulence in flow through the blood separationchamber 34. In another embodiment, the controller may be configured todetermine particulate flow in the blood separation chamber 34. In yetanother embodiment, the controller may be configured to determineabsolute intensity of light in the blood separation chamber 34. In stillanother embodiment, the controller is configured to determine hemolysisof blood cells in the blood separation chamber 34. In anotherembodiment, the controller is configured to determine the hematocrit ofblood in the blood separation chamber 34. In yet another embodiment, thecontroller is configured to determine cell type of blood cells in theblood separation chamber 34. In still another embodiment, the controlleris configured to determine lipemia in blood in the blood separationchamber 34. The controller may be configured to simultaneously determinetwo or more of these characteristics. Once determined, one or more ofthese characteristics may be used in estimating the yield of a separatedblood component, determining white blood cell contamination, orcalculating any of a number of other values.

As described above, in one embodiment, the light detector 160 isprovided as a two-dimensional array sensor. A similar result may beachieved with a linear array sensor in a scanning mode or atwo-dimensional array sensor in a strobed, single-shot mode. Atwo-dimensional array sensor may also be used as a linear array sensor(e.g., by examining only a single row or column thereof), meaning that amonitoring system 156 having such an light detector 160 may haveimproved flexibility in allowing an operator or technician to choosebetween using the light detector 160 as either a linear ortwo-dimensional array sensor. If the light detector 160 is provided andused as a two-dimensional array sensor, it may be advantageous tooperate the light source 160 in a stroboscopic illumination mode toreduce image-smearing and distortion.

In addition to determining characteristics of fluid flow, the monitoringsystem 156 may also be employed to determine characteristics of the flowcircuit itself. Other optical monitoring systems, including suitablyconfigured known and novel systems, may also be employed in connectionwith determining characteristics of the flow circuit itself, although itmay be advantageous to employ optical monitoring systems according tothe present disclosure for ease of extracting and analyzing informationfrom received images. For example, FIG. 15 illustrates a bloodseparation chamber 166 of a flow circuit incorporating a region 168 withat least one identification feature 170 (FIG. 16). The identificationfeature 170 is configured to be detected by an optical monitoring systemwhen the blood separation chamber 166 is received inside the centrifuge52. The region 168 is positioned such that it is visible by an opticalmonitoring system. If the optical monitoring system is positionedoutside of the centrifuge 52, the centrifuge bowl 54 may include anadditional window or transparent region generally aligned with theregion 168. Alternatively, the region 168 and the identification feature170 may be positioned so as to overlay the ramp 152 and be visiblethrough the above-described window 162 of the centrifuge bowl 54.

The optical monitoring system detects the presence (or lack thereof) ofthe identification feature 170 and then a controller associated with themonitoring system compares the detected identification feature to anexpected identification feature. The expected identification featurecorresponds to the identification feature of a blood separation chamberthat is suitable for use with the separation device or for a particularblood processing operation carried out by the separation device. If thedetected identification feature does not match the expectedidentification feature, it is an indication that the flow circuit is notapproved for or suitable for use with the separation device 10. In thiscase, the controller may generate an alarm condition to alert anoperator or technician that the flow circuit is not suitable and thatthe separation device will not initiate a blood separation procedureuntil the flow circuit has been replaced. On the other hand, if thedetected identification feature does match the expected identificationfeature, it is an indication that the flow circuit is approved for orsuitable for use with the separation device 10. In this case, thecontroller may initiate a blood separation procedure or otherwise allowthe procedure to commence.

The identification feature 170 may be variously configured withoutdeparting from the scope of the present disclosure. In one embodiment,the identification feature 170 comprises a printed image, such as (butnot limited to) a barcode. In another embodiment, the identificationfeature 170 comprises a portion of the blood separation chamber 166having a material thickness different from the material thickness of theblood separation chamber 166 adjacent to the identification feature 170.In yet another embodiment, the identification feature 170 comprises amaterial contour different from a material contour of the bloodseparation chamber 166 adjacent to the identification feature 170. Inanother embodiment, the identification feature 170 comprises a region orsecond material having a different opacity from the opacity of thematerial of the blood separation chamber 166 adjacent to theidentification feature 170. Any other optically detectableidentification feature or a combination of different types ofidentification features may also be employed.

An optical monitoring system 156 according to the present disclosure (orany other suitable known or novel monitoring system) may also beemployed to determine whether the flow circuit is properly alignedwithin the centrifuge 52. For example, FIG. 17 illustrates a bloodseparation chamber 172 of a flow circuit incorporating at least onealignment feature 174. The alignment feature 174 is configured to bedetected by an optical monitoring system when the blood separationchamber 172 is received inside the centrifuge 52 (FIG. 17). If theoptical monitoring system is positioned outside of the centrifuge 52,the centrifuge bowl 54 may include an additional window or transparentregion generally aligned with the alignment feature 174. Alternatively,the alignment feature 174 may be positioned so as to overlay the ramp152 and be visible through the above-described window 162 of thecentrifuge bowl 54.

The optical monitoring system detects the presence (or lack thereof) ofthe alignment feature 174 and then a controller associated with themonitoring system compares the detected alignment feature to an expectedalignment feature. This may include comparing the detected position ofthe alignment feature to an expected position of the alignment feature.The expected alignment feature corresponds to the alignment feature of ablood separation chamber that is properly aligned within the centrifuge52 and that it is safe for a particular blood processing operation to becarried out by the separation device. If the detected alignment featuredoes not match the expected alignment feature, it is an indication thatthe flow circuit was not properly installed within the centrifuge 52. Inthis case, the controller may generate an alarm condition to alert anoperator or technician that the flow circuit is not properly installedand that the separation device will not initiate a blood separationprocedure until the flow circuit has been reinstalled. On the otherhand, if the detected alignment feature does match the expectedalignment feature, it is an indication that the flow circuit has beenproperly installed. In this case, the controller may initiate a bloodseparation procedure or otherwise allow the procedure to commence. Themonitoring system may be configured to periodically monitor thealignment feature 174 and, if the detected alignment feature does notmatch the expected alignment feature (e.g., if the blood separationchamber 172 becomes misaligned during use of the separation device), thecontroller may generate an alarm condition and pause or terminate theprocedure.

The alignment feature 174 may be variously configured without departingfrom the scope of the present disclosure. In the illustrated embodiment,the identification feature 174 comprises four markers arranged to belocated adjacent to the four corners of the window 162 of the centrifugebowl 54 when the blood separation chamber 172 is properly positionedwithin the centrifuge 52. If the four markers are not detected in theirexpected locations, it is an indication that the blood separationchamber 172 has been improperly installed.

As an alternative to employing optically detected alignment features,other means may be provided to ensure proper alignment of the bloodseparation chamber within the centrifuge. For example, the bloodseparation chamber and centrifuge may be provided with magneticcomponents or markers, requiring the proper alignment of the two for themagnetic components to be coupled together.

Aspects of the present subject matter described above may be beneficialalone or in combination with one or more other aspects. Without limitingthe foregoing description, in accordance with one aspect of the subjectmatter herein, there is provided a disposable flow circuit for use in ablood processing system of the type including a centrifuge and anoptical monitoring system. The circuit includes a blood separationchamber configured to be at least partially received inside thecentrifuge for the flow of whole blood and/or a separated bloodcomponent therethrough. The circuit also includes an inlet tube for theflow of whole blood into the blood separation chamber and an outlet tubefor the flow of a separated blood component out of the blood separationchamber. The blood separation chamber includes at least oneidentification feature configured to be detected by the monitoringsystem when the blood separation chamber is received inside thecentrifuge to verify that the blood separation chamber is suitable foruse with the centrifuge.

In accordance with another aspect which may be used or combined with thepreceding aspect, the identification feature comprises a barcode.

In accordance with another aspect which may be used or combined with thefirst aspect, the identification feature comprises a printed image.

In accordance with another aspect which may be used or combined with thefirst aspect, the identification feature comprises a material thicknessdifferent from the material thickness of the blood separation chamberadjacent to said at least one identification feature.

In accordance with another aspect which may be used or combined with thefirst aspect, the identification feature comprises a material contourdifferent from the material contour of the blood separation chamberadjacent to said at least one identification feature.

In accordance with another aspect which may be used or combined with thefirst aspect, the identification feature comprises an opacity differentfrom the opacity of the blood separation chamber adjacent to said atleast one identification feature.

In accordance with another aspect which may be used or combined with anyof the preceding aspects, the blood separation chamber includes at leastone alignment feature configured to be detected by the monitoring systemwhen the blood separation chamber is received inside the centrifuge toverify that the blood separation chamber is properly aligned within thecentrifuge.

In accordance with another aspect, there is provided a method ofidentifying a disposable flow circuit in a blood processing system. Themethod includes positioning at least a portion of a disposable flowcircuit in a centrifuge and monitoring the disposable flow circuit todetect the presence of an expected identification feature. An alarmcondition is generated if the expected identification feature is notdetected, while a blood separation procedure is initiated if theexpected identification feature is detected.

In accordance with another aspect which may be used or combined with thepreceding aspect, the expected identification feature comprises a barcode.

In accordance with another aspect which may be used or combined with theeight aspect, the expected identification feature comprises a printedimage.

In accordance with another aspect which may be used or combined with theeight aspect, the expected identification feature comprises a portion ofthe disposable flow circuit having a material thickness different fromthe material thickness of the disposable flow circuit adjacent to saidportion.

In accordance with another aspect which may be used or combined with theeight aspect, the expected identification feature comprises a portion ofthe disposable flow circuit having a material contour different from amaterial contour of the disposable flow circuit adjacent to saidportion.

In accordance with another aspect which may be used or combined with theeight aspect, the expected identification feature comprises a portion ofthe disposable flow circuit having an opacity different from the opacityof the disposable flow circuit adjacent to said portion.

In accordance with another aspect which may be used or combined with anyof the preceding six aspects, monitoring the disposable flow circuitoccurs through a window of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding seven aspects, the method further comprises a step ofmonitoring the disposable flow circuit to detect the presence of anexpected alignment feature. An alarm condition is generated if theexpected identification feature or the alignment feature is notdetected, while the blood separation procedure is carried out if theexpected identification feature and the alignment feature are detected.

In accordance with another aspect, there is provided a disposable flowcircuit for use in a blood processing system of the type including acentrifuge and an optical monitoring system. The circuit comprises ablood separation chamber configured to be at least partially receivedinside the centrifuge for the flow of whole blood and/or a separatedblood component therethrough. The circuit also includes an inlet tubefor the flow of whole blood into the blood separation chamber and anoutlet tube for the flow of a separated blood component out of the bloodseparation chamber. The blood separation chamber includes at least onealignment feature configured to be detected by the monitoring systemwhen the blood separation chamber is received inside the centrifuge toverify that the blood separation chamber is properly aligned within thecentrifuge.

In accordance with another aspect, there is provided a method ofidentifying a disposable flow circuit in a blood processing system. Themethod includes positioning at least a portion of a disposable flowcircuit in a centrifuge and monitoring the disposable flow circuit todetect the presence of an expected alignment feature. An alarm conditionis generated if the expected alignment feature is not detected, while ablood separation procedure is initiated if the expected alignmentfeature is detected.

In accordance with another aspect which may be used or combined with thepreceding aspect, monitoring the disposable flow circuit occurs througha window of the centrifuge.

In accordance with another aspect, there is provided a blood processingsystem. The system comprises a disposable flow circuit, a centrifuge,and a monitoring system. The disposable flow circuit is configured forthe flow of whole blood and/or a separated blood component therethrough.The centrifuge is configured to receive at least a portion of thedisposable flow circuit and separate at least one blood component fromblood flowing through the disposable flow circuit. The monitoring systemis configured to directly monitor the disposable flow circuit receivedby the centrifuge and includes a light source, a light detector, and acontroller. The light source is configured to illuminate said at least aportion of the disposable flow circuit received by the centrifuge. Thelight detector is configured to receive an image of said at least aportion of the disposable flow circuit. The controller is configured tocombine two or more of the images received by the light detector,generate a two-dimensional output, and control the separation of said atleast one blood component from the blood in the disposable flow circuitbased at least in part on said output.

In accordance with another aspect which may be used or combined with thepreceding aspect, the light detector is configured to receive aone-dimensional image of said at least a portion of the disposable flowcircuit.

In accordance with another aspect which may be used or combined with anyof the preceding two aspects, the light detector comprises a lineararray-type sensor.

In accordance with another aspect which may be used or combined with thenineteenth aspect, the light detector is configured to receive atwo-dimensional image of said at least a portion of the disposable flowcircuit.

In accordance with another aspect which may be used or combined with thenineteenth or twenty-second aspects, the light detector comprises atwo-dimensional array sensor.

In accordance with another aspect which may be used or combined with anyof the preceding five aspects, the controller is configured to determinethe location of an interface between two separated blood components andmove the interface toward a desired location within the disposable flowcircuit.

In accordance with another aspect which may be used or combined with anyof the preceding six aspects, the monitoring system is positionedoutside of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding seven aspects, the centrifuge includes a window throughwhich the monitoring system directly monitors said at least a portion ofthe disposable flow circuit received by the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding eight aspects, a scan rate of the light detector iscoupled to a rotational speed of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding nine aspects, the controller is configured to determineturbulence in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding ten aspects, the controller is configured to determineparticulate flow in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding eleven aspects, the controller is configured todetermine absolute intensity of light in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding twelve aspects, the controller is configured todetermine hemolysis of blood cells in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding thirteen aspects, the controller is configured todetermine hematocrit of blood in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding fourteen aspects, the controller is configured todetermine cell type of blood cells in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding fifteen aspects, the controller is configured todetermine lipemia in blood in the disposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding sixteen aspects, the disposable flow circuit includesat least one identification feature and the controller is configured todetect the presence of said at least one identification feature.

In accordance with another aspect which may be used or combined with anyof the preceding seventeen aspects, the controller is configured todetermine whether said at least a portion of the disposable flow circuitis properly aligned within the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding eighteen aspects, the light source is configured tocontinuously illuminate said at least a portion of the disposable flowcircuit during a monitoring state.

In accordance with another aspect which may be used or combined with anyof the preceding nineteen aspects, the system further comprises aplurality of light sources, wherein at least two of the light sourceshave different wavelengths.

In accordance with another aspect which may be used or combined with thepreceding aspect, the plurality of light sources are configured to beoperated sequentially.

In accordance with another aspect which may be used or combined with anyof the preceding twenty-one aspects, the light source is configured toprovide stroboscopic illumination to said at least a portion of thedisposable flow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding twenty-two aspects, the light source includes anelectronic timing system configured to selectively operate the lightsource when an area of interest of said at least a portion of thedisposable flow circuit is in the field of view of the monitoringsystem.

In accordance with another aspect which may be used or combined with thepreceding aspect, the electronic timing system includes an opticaltriggering mechanism.

In accordance with another aspect which may be used or combined with theforty-first aspect, the electronic timing system includes a mechanicaltriggering mechanism.

In accordance with another aspect which may be used or combined with theforty-first aspect, the electronic timing system includes a magnetictriggering mechanism.

In accordance with another aspect which may be used or combined with theforty-first aspect, the system further includes a motor, with theelectronic timing system including a triggering mechanism based at leastin part on the rotational location of the motor.

In accordance with another aspect which may be used or combined with anyof the preceding twenty-seven aspects, the disposable flow circuitand/or the centrifuge includes a calibration marker positioned adjacentto an area of interest of said at least a portion of the disposable flowcircuit.

In accordance with another aspect which may be used or combined with thepreceding aspect, a monitoring state of the light detector is initiatedupon detection of the calibration marker.

In accordance with another aspect which may be used or combined with anyof the preceding two aspects, the calibration marker has a knownbrightness and the controller is configured to adjust the operation ofthe light source and/or the light detector based on a comparison of adetected brightness of the calibration marker to the known brightness.

In accordance with another aspect, there is provided a method ofcontrolling a blood separation procedure. The method includes separatingat least one blood component from blood in a centrifuge and applyinglight to the interior of the centrifuge. An image of the interior of thecentrifuge is received and two or more of such images are combined. Atwo-dimensional output is generated based, at least in part, on said twoor more of said images and the separation of said at least one bloodcomponent from the blood in the centrifuge is controlled based, at leastin part, on said two-dimensional output.

In accordance with another aspect which may be used or combined with thepreceding aspect, receiving an image includes receiving aone-dimensional image of the interior of the centrifuge.

In accordance with another aspect which may be used or combined with theforty-ninth aspect, receiving an image includes receiving atwo-dimensional image of the interior of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding three aspects, generating a two-dimensional outputincludes determining the location of an interface between two separatedblood components and said controlling the separation includes moving theinterface toward a desired location within the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding four aspects, applying light and receiving an imageoccur at a position outside of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding five aspects, receiving an image occurs at a scan ratewhich is coupled to a rotational speed of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding six aspects, generating a two-dimensional outputincludes determining turbulence in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding seven aspects, generating a two-dimensional outputincludes determining particulate flow in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding eight aspects, generating a two-dimensional outputincludes determining absolute intensity of light in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding nine aspects, generating a two-dimensional outputincludes determining hemolysis of blood cells in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding ten aspects, generating a two-dimensional outputincludes determining hematocrit of blood in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding eleven aspects, generating a two-dimensional outputincludes determining cell type of blood cells in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding twelve aspects, generating a two-dimensional outputincludes determining lipemia in blood in the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding thirteen aspects, separating at least one bloodcomponent includes separating at least one blood component in blood in adisposable flow circuit at least partially received inside of thecentrifuge, and generating a two-dimensional output includes detectingthe presence of at least one identification feature of the disposableflow circuit.

In accordance with another aspect which may be used or combined with anyof the preceding fourteen aspects, separating at least one bloodcomponent includes separating at least one blood component in blood in adisposable flow circuit at least partially received inside of thecentrifuge, and generating a two-dimensional output includes determiningwhether the disposable flow circuit is properly aligned within thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding fifteen aspects, applying light includes applying aplurality of lights having different wavelengths.

In accordance with another aspect which may be used or combined with thepreceding aspect, applying light includes operating the lightssequentially.

In accordance with another aspect which may be used or combined with anyof the preceding seventeen aspects, applying light includes providingstroboscopic illumination to the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding eighteen aspects, applying light includes continuouslyapplying light to the centrifuge during a monitoring state.

In accordance with another aspect which may be used or combined with anyof the preceding nineteen aspects, applying light includes selectivelyapplying light when an area of interest of the centrifuge is in thefield of view of the light. In accordance with another aspect which maybe used or combined with the preceding aspect, applying light isoptically triggered.

In accordance with another aspect which may be used or combined with thesixty-eighth aspect, said applying light is mechanically triggered.

In accordance with another aspect which may be used or combined with thesixty-eighth aspect, said applying light is magnetically triggered.

In accordance with another aspect which may be used or combined with thesixty-eighth aspect, applying light is triggered based at least in parton the rotational location of a motor.

In accordance with another aspect which may be used or combined with anyof the preceding twenty-four aspects, separating at least one bloodcomponent includes separating at least one blood component in blood in adisposable flow circuit at least partially received in the centrifuge.The disposable flow circuit and/or the centrifuge includes a calibrationmarker positioned adjacent to an area of interest of the disposable flowcircuit, and a monitoring state is initiated upon detection of thecalibration marker.

In accordance with another aspect, there is provided a blood processingsystem comprising a centrifuge bucket, a centrifuge, and a monitoringsystem. The centrifuge is positionable within the centrifuge bucket andconfigured to receive at least a portion of a disposable flow circuit toseparate at least one blood component from blood flowing through thedisposable flow circuit. The monitoring system is configured to directlymonitor a disposable flow circuit received by the centrifuge when thecentrifuge is positioned within the centrifuge bucket, wherein themonitoring system is positioned outside of the centrifuge bucket.

In accordance with another aspect which may be used or combined with thepreceding aspect, the centrifuge includes a window through which themonitoring system directly monitors a disposable flow circuit receivedby the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding two aspects, the monitoring system comprises a lightsource and a light detector. The light source is configured toilluminate a disposable flow circuit received by the centrifuge. Thelight detector is configured to receive an image of the disposable flowcircuit.

In accordance with another aspect which may be used or combined with thepreceding aspect, the light detector is configured to receive aone-dimensional image of a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding two aspects, the light detector comprises a lineararray-type sensor.

In accordance with another aspect which may be used or combined with theseventy-sixth aspect, the light detector is configured to receive atwo-dimensional image of a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with theseventy-sixth or the preceding aspect, the light detector comprises atwo-dimensional array sensor.

In accordance with another aspect which may be used or combined with anyof the preceding five aspects, a scan rate of the light detector iscoupled to a rotational speed of the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding six aspects, the light source is configured tocontinuously illuminate a disposable flow circuit received by thecentrifuge during a monitoring state.

In accordance with another aspect which may be used or combined with anyof the preceding seven aspects, the system includes a plurality of lightsources, wherein at least two of the light sources have differentwavelengths.

In accordance with another aspect which may be used or combined with thepreceding aspect, the plurality of light sources are configured to beoperated sequentially.

In accordance with another aspect which may be used or combined with anyof the preceding nine aspects, the light source is configured to providestroboscopic illumination to a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding ten aspects, the light source includes an electronictiming system configured to selectively operate the light source when anarea of interest of a disposable flow circuit received by the centrifugeis in the field of view of the monitoring system.

In accordance with another aspect which may be used or combined with thepreceding aspect, the electronic timing system includes an opticaltriggering mechanism.

In accordance with another aspect which may be used or combined with theeighty-sixth aspect, the electronic timing system includes a mechanicaltriggering mechanism.

In accordance with another aspect which may be used or combined with theeighty-sixth aspect, the electronic timing system includes a magnetictriggering mechanism.

In accordance with another aspect which may be used or combined with theeighty-sixth aspect, the system includes a motor, wherein the electronictiming system includes a triggering mechanism based at least in part onthe rotational location of the motor.

In accordance with another aspect which may be used or combined with anyof the preceding fifteen aspects, the system includes a controllerconfigured to combine two or more of the images received by the lightdetector and generate a two-dimensional output used for controlling theseparation of said at least one blood component from the blood in adisposable flow circuit received by the centrifuge.

In accordance with another aspect which may be used or combined with thepreceding aspect, the controller is configured to determine turbulencein a disposable flow circuit received by the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding two aspects, the controller is configured to determineparticulate flow in a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding three aspects, the controller is configured todetermine absolute intensity of light in a disposable flow circuitreceived by the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding four aspects, the controller is configured to determinehemolysis of blood cells in a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding five aspects, the controller is configured to determinehematocrit of blood in a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding six aspects, the controller is configured to determinecell type of blood cells in a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding seven aspects, the controller is configured todetermine lipemia in blood in a disposable flow circuit received by thecentrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding eight aspects, the system includes a disposable flowcircuit configured to be at least partially received by the centrifuge,wherein the controller is configured to determine whether the disposableflow circuit is properly aligned within the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding nine aspects, the system includes a disposable flowcircuit configured to be at least partially received by the centrifuge,wherein the disposable flow circuit includes at least one identificationfeature and the controller is configured to detect the presence of saidat least one identification feature.

In accordance with another aspect which may be used or combined with thepreceding aspect, the identification feature comprises a barcode.

In accordance with another aspect which may be used or combined with theone hundredth aspect, the identification feature comprises a printedimage.

In accordance with another aspect which may be used or combined with theone hundredth aspect, the identification feature comprises a materialthickness different from the material thickness of the disposable flowcircuit adjacent to said at least one identification feature.

In accordance with another aspect which may be used or combined with theone hundredth aspect, the identification feature comprises a materialcontour different from the material contour of the disposable flowcircuit adjacent to said at least one identification feature.

In accordance with another aspect which may be used or combined with theone hundredth aspect, the identification feature comprises an opacitydifferent from the opacity of the disposable flow circuit adjacent tosaid at least one identification feature.

In accordance with another aspect which may be used or combined with anyof the preceding fifteen aspects, the controller is configured todetermine the location of an interface between two separated bloodcomponents and move the interface toward a desired location within adisposable flow circuit received by the centrifuge.

In accordance with another aspect which may be used or combined with anyof the preceding sixteen aspects, the system includes a disposable flowcircuit configured to be at least partially received by the centrifuge,wherein the disposable flow circuit and/or the centrifuge includes acalibration marker positioned adjacent to an area of interest of thedisposable flow circuit.

In accordance with another aspect which may be used or combined with thepreceding aspect, a monitoring state of the light detector is initiatedupon detection of the calibration marker.

In accordance with another aspect which may be used or combined with anyof the preceding two aspects, the calibration marker has a knownbrightness and the controller is configured to adjust the operation ofthe light source and/or the light detector based on a comparison of adetected brightness of the calibration marker to the known brightness.

It will be understood that the embodiments described above areillustrative of some of the applications of the principles of thepresent subject matter. Numerous modifications may be made by thoseskilled in the art without departing from the spirit and scope of theclaimed subject matter, including those combinations of features thatare individually disclosed or claimed herein. For these reasons, thescope hereof is not limited to the above description but is as set forthin the following claims, and it is understood that claims may bedirected to the features hereof, including as combinations of featuresthat are individually disclosed or claimed herein.

The invention claimed is:
 1. A blood processing system, comprising: adisposable flow circuit configured for the flow of whole blood and/or aseparated blood component therethrough; a centrifuge configured toreceive at least a portion of the disposable flow circuit and rotateabout a rotational axis to separate at least one blood component fromblood flowing through the disposable flow circuit; and a monitoringsystem configured to directly monitor the disposable flow circuitreceived by the centrifuge and comprising a light source configured toilluminate said at least a portion of the disposable flow circuitreceived by the centrifuge, a plurality of light detectors eachconfigured to receive an image of said at least a portion of thedisposable flow circuit, and a controller configured to combine two ormore of the images received by the plurality of light detectors,generate a two-dimensional output, and control the separation of said atleast one blood component from the blood in the disposable flow circuitbased at least in part on said output, wherein the monitoring system isconfigured to cause the light source to continuously illuminate said atleast a portion of the disposable flow circuit during separation of saidat least one blood component from the blood in the disposable flowcircuit, the plurality of light detectors comprise photodiodesincorporated into a linear array-type sensor and positioned at differentlocations in a direction parallel to the rotational axis, and the two ormore images are sequentially received by adjacent light detectors beforebeing combined by the controller.
 2. The blood processing system ofclaim 1, wherein each one of the plurality of light detectors isconfigured to receive a one-dimensional image of said at least a portionof the disposable flow circuit.
 3. The blood processing system of claim1, wherein the controller is configured to determine the location of aninterface between two separated blood components and move the interfacetoward a desired location within the disposable flow circuit.
 4. Theblood processing system of claim 1, wherein the controller is configuredto determine at least one of: turbulence, particulate flow, absoluteintensity of light, hemolysis of blood cells, hematocrit of blood, celltype of blood cells, and lipemia in blood in the disposable flowcircuit.
 5. The blood processing system of claim 3, wherein thecontroller is configured to examine an entire length of the interface.6. The blood processing system of claim 3, wherein the controller isconfigured to determine a thickness of the interface.
 7. The bloodprocessing system of claim 3, wherein the controller is configured todetermine whether the interface is angled.
 8. The blood processingsystem of claim 1, wherein the controller is configured tosimultaneously determine at least two of: turbulence, particulate flow,absolute intensity of light, hemolysis of blood cells, hematocrit ofblood, cell type of blood cells, and lipemia in blood in the disposableflow circuit.